Retopology and baking normals for double-sided (thick) clothes from Marvellous Designer workflow
This works to some extent:

Flip the normal of the inner faces
Bake the Object Space normal
Connect it in your material shader graph, even though your normal is in Object Space, use Tangent Space in your Normal Map node.
Create a new image, select it and now bake the normal map, but this time use Tangent Space.

If anyone knows the better workflow, please share it :)